USB flash drives are easy to lose if you don't keep track of them. In part three of our "What to do with your USB flash drive" series, we'll show you how to encrypt your USB flash drive so that if it gets lost or stolen, its contents will be safe and sound:

Step 7: At the Encryption Options screen, leave the defaults unless you specifically want to change the algorithms. Click Next to continue.

Step 8: At the Volume Size screen, all the selections should be grayed out and will display the total size of your USB flash drive. Click Next to continue.

Step 9: At the Volume Password screen, type in your password twice. TrueCrypt recommends a password consisting of 20 characters or more. Click Next to continue.

Step 10: At the Large Files screen, select No, then click Next.

Step 11: At the Volume Format screen, move your mouse randomly on the screen. The longer you move the mouse around, the stronger the encryption will be. When you're done, click on the Format button. When the confirmation dialog comes up, read it for accuracy and click the Yes button.

Screenshot by Ed Rhee

Once the formatting has completed, exit the TrueCrypt Volume Creation Wizard.

Decrypt it In order to decrypt the USB flash drive, you have to mount the encrypted partition--in our case, the entire USB flash drive--to a virtual drive letter.

You should now see the drive letter you chose in Windows Explorer. This is your encrypted drive. Store anything you'd like in this drive to keep it encrypted. Note that you must use the mounted drive letter, not the drive letter that shows up when you insert the USB flash drive.

There you go. Now you if you lose your USB flash drive, you can feel safe knowing that nobody will be able to access the files on it.